you had better drive carefully .the roads are wet
问题描述:
you had better drive carefully .the roads are wet
为嘛不能用would better
答
要放在语境中间理解.可能这个开车的人 已经出了什么交通事故,所以其它人才提醒他刚刚应该小心开车,因为路是湿的.